Tha aims of this research project are: 1) to evaluate the effect of maternal glucose and amino acid insulin sensitivity on fetal placental growth and development, 2) to determine if neonatal growth and carbohydrate metabolism during the first year of life reflect the effect of "metabolic imprinting" in utero and 3) to explore the role of alteration in glucose transporters as a potential mechanism for the changes in maternal insulin sensitivity and placental glucose capacity.